Evaluation of Morphodynamic Controls on the Preservation of Fluvial Meander‐Belt Deposits

Autor: N. Yan, L. Colombera, N. P. Mountney
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Geophysical Research Letters, Vol 48, Iss 16, Pp n/a-n/a (2021)
Druh dokumentu: article
ISSN: 1944-8007
0094-8276
DOI: 10.1029/2021GL094622
Popis: Abstract The way river morphodynamics influence the preservation of point‐bar deposits at multiple scales is not fully understood. Employing time‐lapse trajectories of natural rivers, a numerical model is used here to simulate planform evolutions of meander‐belt reaches that embody different transformation behaviors and cutoff processes. Proxies for temporal durations are obtained considering the surface area over which a river migrated and channel migration rates that relate to average channel radius of curvature through constant, monotonic, and non‐monotonic relationships. The preservation of meander‐belt deposits over different timescales is assessed at three architectural hierarchies: (a) pairs and (b) sets of accretion packages, and (c) meander‐belts. Results confirm that sediment preservation decreases in a predictable way with the accumulation time; however, accretion rates decay with time in a way that does not follow the expected power‐law. This is interpreted to reflect the effect of the onset of geomorphic thresholds of channel transformation and cutoff.
Databáze: Directory of Open Access Journals
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